I need help

I could not play Mov video shot on iPhone, there was only sound, I installed the mega package, a picture appeared, but it jerks. How can this problem be solved?

Hi, this is what you should do first.

1.) Remove/uninstall any fake codecs (Shark Codecs) using Add and Remove Programs in Conte Panel
2.) Re-download K-Lite Mega installer from the official website http://codecguide.com/download_k-lite_codec_pack_mega.htm
3.) Re-install K-Lite Mega using only default settings
4.) If you use Windows 7: open Media Player Classic, go to View - Options - Formats, click "V" button described "Associate with video formats only", press OK. If you use Windows 10: go to Start - Settings - System - Default apps, open "Video player" menu and select MPC-HC.
5.) Close all open applications and programs (Web Browser, Chat applications)... But don't close your anti-virus of course.
6.) Play the video again. If the video stutters again after you do all that, then you CPU is probably too weak or is at a high temperature. You can check that too later, if you wish.

If you have a new iphone then the video is probably in HEVC format. That is relatively difficult to decode on devices that don't have hardware acceleration for that format.

Right-click on the mov file in Explorer, and select MediaInfo. That shows details about the file format.

Codec Tweak Tool > Generate Log
If you copy that information here, then I can see if your system is capable of playback or if it is too old.